Artificial intelligence advancements for orthopaedic clinical reasoning: longitudinal assessment of newer models (ChatGPT-5, Grok-3, Gemini 2.5 Flash) compared to clinicians

Abstract

This descriptive study aimed to longitudinally evaluate the performance of contemporary large language models - ChatGPT-5, Gemini 2.5 Flash, and Grok-3 - on orthopaedic clinical multiple-choice tasks, benchmarked against pooled clinician consensus. A secondary aim was to assess whether recent advances in generative AI translated into improved alignment with clinician consensus compared with previous AI models. A total of 97 multiple-choice clinical cases spanning eight orthopaedic subspecialties were sourced from OrthoBullets and previously benchmarked against aggregated responses from thousands of practising clinicians. Using identical methodology to our 2023 study of ChatGPT-3.5, ChatGPT-4, and Bard, each model was prompted with standardised case stems and response options. The primary outcome was the proportion of AI responses matching the most popular clinician response; secondary analyses assessed agreement within 10% and 20% of clinician consensus, performance on ‘controversial’ (< 25% margin) questions, and inter-model concordance using Cohen’s kappa coefficients. Gemini 2.5 Flash achieved the highest alignment with clinician consensus (69.1%), followed by Grok-3 (66.0%) and ChatGPT-5 (58.8%). None of the LLMs refused to respond to any prompts, representing a reduction from 7.2% from our 2023 study. Subspecialty analysis demonstrated that Gemini 2.5 Flash performed best in Hand and Paediatric domains, while Grok-3 excelled in Reconstruction, Trauma, and ‘controversial’ cases. Inter-model agreement was highest between Grok-3 and Gemini 2.5 Flash (κ = 0.678), indicating improved consistency compared with prior-generation systems. Contemporary LLMs can be promising adjuncts for orthopaedic education by simulating peer reasoning and offering structured explanations in non-critical settings. Despite incremental gains in reasoning capability compared to previous AI models, contemporary LLMs remain unsuitable for independent clinical use. Future research should develop hybrid clinician–AI workflows and longitudinal benchmarks to distinguish true reasoning improvements from memorisation.